Battery cell and unit



Jan. 2, 1951 I s, RUBEN 2,536,698

' BATTERY CELL AND UNIT Filed April 23, 1946 I NVENTO R Jamal] Zaiwz/nzyme, $13

ATTORNEY tion embodying a vnections to each cell.

Patented Jan. 2, 1951 UNITED STATES PATENT orncs Application April 23,1946, Serial No. 664,163 4 Claims. (Cl. 136111) relates to a batteryconstrucplurality of cells which is particularly adapted to supplyelectrical energy for a hearing aid device.

An object of this invention is to provide an improved batteryconstruction and animproved cell arrangement for such battery.

Other objects of the invention will be apparent from the followingdescription and accompanying drawings taken in connection with theappended claims.

The invention accordingly comprises the features of construction,combination of elements, arrangement of parts, and methods ofmanufacture referred to above or which will be brought out andexemplified in the disclosure hereinafter set forth, including theillustrations in the drawings, the scope of the invention beingindicated in the appended claims.

In the drawings:

Figure 1 is a perspective view of a battery casin Figure 2 is a planview, partially in section, of the interior of the battery shown inFigure 1.

Figures 3 and 4 are schematic circuit diagrams showing the connectionsof the cells in the baty;

Figure 5 is a perspective view of a battery cell;

Figure 6 is a sectional view, partially in elevation, of the cell shownin Figure 5 with the parts in disassembled relation; and

Figure 'I is a sectional view, partially in elevation, of a modifiedbattery construction.

' According to this invention, a readily portable battery is providedembodying a plurality of cells assembled, in a novel manner, within abattery case. A feature of the invention resides in the assembly ofparts to provide a cell having partially sealed interior portions,the'arrangement of such cells into stacks and the application ofpressure tothe stacks after they are positioned within a battery casewhereby the parts of each cell are forced into completely sealedassembled relation and a good electrical connection is provided betweenadjacent cell terminals. Consequently, it is not necessary to assembleand seal each cell individually, as by spinning over the top of thecell, nor to solder or otherwise secure terminal con- The cell stacksare connected in circuit by simple and readily adjustable contactmembers disposed within the battery cas- This invention ing to supplythe proper voltage and current-toa hearing aid or other electricaldevice, such connections also being efiected without soldering or theuseof wire conductors so that the entire batout departing from thespirit of the invention. 7

In the following description and in the claims, parts will be identifiedby specific names for convenience, but they are intended to be asgeneric 0 in their application to similar parts as the art will permit.

Referring now to the drawings in detail, and particularly to Figures 1and 2, the battery may comprise a plurality of cells l0 mounted andassembled, in the manner hereinafter described, .in a case H of anyconvenient size which may be adapted, for example, to fit into thepocket of the user. A cover I2 may be secured to the case as by rivetsI3 and such cover together with the case ll may be formed from moldedBakelite or other Suitable insulating material which may have anornamental outer surface, if desired.

The component parts of each cell, prior to assembly thereof into astack, may include a bimetal cup i4, Figures 5 and 6, comprising anexternal steel layer l5 and an inner zinc layer It. The anode of thecell may be a compressed pellet i1, preferably formed from amalgamatedzinc powder containing about 0.05% lead and about 0.002% cadmium, whichis mounted in the cup 14 and contacts the inner zinc layer IS. The anodeassembly further includes a spacer l8 mounted within a polystyrene ringl9, said spacer l8 consisting of several discs of a porous high puritypaper, such as Dexter paper, which may be impregnated, as will beunderstood by those skilled in the art, with a suitable electrolyte. Iprefer to use an electrolyte consisting of 30 to 100 grams of potassiumcarbonate in 100 milliliters of water to impregnate the spacer l8, itbeing understood that the excess electrolyte is .drained off before thespacer is mounted in the anode assembly.

As an alternative to using the spacer it impregnated with a potassiumcarbonate electrolyte, I may utilize a disc of felted cotton paper whichhas been treated in the manner now to be described. This disc may bepunched from a sheet which has been immersed in an electrolyteconsisting of 100 grams of potassium hydroxide (88%), 16 grams of zincoxide, and 5 grams of sodium carboxymethylcellulose dissolved in 100milliliters of water. I prefer to vacuum-impregnate the sheet so as toeliminate air pockets and, after impregnation, the sheet is preferablyplaced in a stainless steel mold and then heated to a temperature aabout 117 to 120 (3., this being slightl below the boiling point of theelectrolyte. It is important that the temperature of the electrolytedoes not rise above the boiling point as this would result in anundesirable porous structure. 'After the heat treatment, the sheetcontaining the impregnated. electrolyte forms a clear transparent gelwhich is sumciently tough and flexible to form a desirable barrierlayer. The width of the mold in which the heat treatment takes place.should be slightly less than the thickness of the impregnated sheet inorder that a smooth surface may be produced.

Each cell also comprises a resilient grommet or sealing ring 20, formed,for example, from rubber or neoprene, which is mounted around the edgeof the cup i4 so as to engage and seal the sides of the cup. The grommetmay be formed from an elastic tube which is stretched to engage the cupin the manner shown or, alternatively, the grommet may be moulded toprovide an L- shaped cross-section. A barrier disc 2|, preferably ofplasticized polyvinyl alcohol or parchment paper, contacts the grommet20 and spacer l8, said barrier disc being eflective to prevent themigration of deleterious particles.

The cathode assembly includes a cap or cover plate 22 within which isdisposed a compressed pellet 23 constituting the cathode-depolarizer ofthe cell. The pellet 23 is preferably composed of 90% red mercuric'oxide and micronized graphite. Although the materials used for theanode, cathode, barrier layer, and potassium carbonate are described inmore detail by my copending application 2,458,878, entitled PrimaryCell, materials used form no part of which, accordingly, is not to beforegoing illustrative description the particular this invention limitedby the thereof.

The cap 22 has an integral cylindrical flange 24, the interior diameterof which is slightly less than the external diameter of the peripheralgrommet portions 25. Accordingly, when the cap is placed in position onthe cup l4, the interior of the cell is partially sealed and the cathodepellet 23 contacts the barrier layer 2!. It will be appreciated,therefore, that the cells may be very rapidly assembled merely bypushing togather the anode assembly and cathode assem bly. Afterassembly, it will be apparent that the cap 22 serves as the positiveterminal of the cell while the cup l4 serves as the negative terminal ofthe cell.

Although the fit between the'grommeted cup and the cap serves topartially seal the interior of the cell, additional sealing isordinarily required to positively prevent the electrolyte from leakingout of the cell and to guarantee a long period of usefulness for thebattery. Such additional sealing is secured, in accordance with theinvention, by assembling the cells into stacks and applying pressure tothe stacks by means of pressure members disposed within the batterycasing to force the cap of each cell into engagement with the associatedgrommet, thus affording additional sealing and insuring good electricalcontact between adjacent cells.

In the embodiment of the invention shown in Figures 2 and 3, each stackcomprises ten cells connected in series with the bottom of each cupengaging the cap of the adjacent cell. Of course, any suitable number ofcells may be used in each stack depending on the voltage desired. Itwill be apparent, therefore, that the cap :2 and the cup l4 at therespective opposite ends 0! the S. N. 60l,626, now Patentstacks arestack constitute the positive and negative stack terminals. The stacksare mounted in suitable compartments defined by a central wall 33 andpanels 3i which are formed from insulating material and integrallymolded with the case II.

In order to facilitate series connection of the stacks to obtain thedesired battery voltage, the mounted in the compartments so thatadjoining stack terminals are of opposite polarities, respectively. Theseries connection may comprise a contact plate 32 for connecting thenegative terminal of stack 33 with the positive terminal of stack 34;contact plates 35 and a conductor rod 36 for connecting the negativeterminal of stack 34 with the positive terminal of stack 31; and acontact plate 33 for connecting the negative terminal of stack 31 withthe positive terminal of stack 33. Contact plates 48 and. are connected,respectively, to the negative terminal of stack 33 and the positiveterminal of stack 33, these plates, in turn, being connected to sleeveinserts 42 and 43, respectively, which are mounted in suitable passagesin the casing H. The sleeve inserts 42, 43 together with a' guideopening 44, Figure 1, are adapted to receive a three pronged connectorplug for making external circuit connections to the battery.

Pressure is applied to each stack of cells through the plates 32 and 38by pressure screws 45, one of which is in alignment with each stock. Thescrews 45 may be mounted in sleeve inserts 46 which are disposed insuitable passages 41 formed in the casing H. Each screw is adjustable tovary the pressure upon the associated stack individually. In thismanner, suflicient pressure is applied to thestacks to force the cap ofeach cell into sealing engagement with the associated cup whereby theelectrolyte is positively retained in the cell without danger of leakageor evaporation. The pressure applied by the screws 45 is also effectiveto insure good electrical contact between adjacent cells of each stackas well as between the stack terminals and the contact plates. Thepassages 41 may conveniently be countersunk as at 43 so that thehead ofeach adjusting screw may be locked in its final position after'thedesired stack pressure is obtained. For this'purpose, melted pitch orwax may be poured into the countersunk portions 43 and allowed toharden.

The schematic diagram of Figure 4 shows an alternative arrangement ofthe battery cells ll.

Ths arrangement of cells may be used in the casing II Figure 2,

by shortening the conductor rod 36 to connect stacks 33 and 33 ratherthan stacks 34 and 31, and-by providing connections from stacks 34 and31 to the external circuit connectors 42 and 43, respectively.Alternatively. the stacks may be connected in parallel or seriesparallelby making obvious changes in the circuit connectors of the battery.

Referring to Figure 7, a. battery com a single stack is shown which maybe used by i if or with other similar units. The cells are assembled inend to end contact in the same general manner and arrangement as hasbeen described herein with respect to the embodiment shown in Figure 2.The stack 43 may be mounted in an elongated container comprising anouter cylindrical, steel sleeve ill having an inner lining ll ofinsu'ating material extending from end to end thereof. A laminatedwasher 32 is mounted in the base of the sleeve 50, said washerpreferably comprising an inner layer of insulating material such asBakelite which contacts the end of the stack and an outer layer ofresilient material such as neoprene. The battery cells H) are compressedby turned over ends 53 of the sleeve with resultant sealing of the cellsand positive contact between adjacent cells. It will be apparent thatconnection may be made to the negative terminal of the stack through thecasing 50 while the positive terminal is accessible through the centralaperture in washer 52.

As illustrative of suitable specifications for the battery, each cellmay be approximately one-half inch long, one-half inch in diameter, andproduce 1.4 volts. Six cells is a suitable number for forming a line orstack although as many cell may be used as desired. The ends of thesteel tube 50, Figure 7, may be rolled over one-eighth inch to providethe end portions 53 and the washer 52- may be approximately one-halfinch in diameter with a one-quarter inch central opening. Eachgrommet'20 may be originally 20 mils thick. The entire stack may becompressed in a suitable press and the sleeve 53 may then be turned orspun over to provide and maintain a compressed thickness of mils in eachgrommet.

While the present invention, as to its objects and advantages, has beendescribed herein as carried out in specific embodiments thereof, it isnot desired to be limited thereby but it is intended to cover theinvention broadly within the spirit and scope of the appended claims.

What is claimed as new and desired to be secured by Letters Patent is:

1; A battery comprising, in combination, a plurality of cells; each ofsaid cells including a substantially non-compressible metal anode shelland a similar cathode shell respectively containing anode and cathodematerials and having outer surfaces constituting terminals for the cell,a grommet of elastic insulative material having a portion extendingsubstantially transversely of the axis of the cell interposed betweencooperating portions of said shells and adapted when compressed by theshells in the axial direction to define with said shells a substantiallyfluid-tight enclosure for the cell, and an electrolyte within saidenclosure and in contact with said anode,

. closures, and low resistance electrical connection of said cells inseries; the non-compressible character of the said metal shellspreventing the possibility of applying destructive pressures upon theindividual cells.

2. The battery claimed in claim 1 in which the means applyingcompression upon the stack of cells are adjustable.

3. The battery claimed in claim 1 in which locking means are providedfor securing the compression applying means.

4. A battery comprising, in combination, a plurality of cells; each ofsaid cells including a substantially non-compressible metal cup, agrommet of elastic insulating material secured to the top of said cuphaving a portion extending inwardly of the rim thereof and having aportion protruding downwardly along the rim thereof, and a substantiallynon-compressible metal cap fitting over said grommet, said cup and saidcap having inner surfaces confining said grommet and having flat outersurfaces constituting terminals of opposite polarity for the cell; saidcells being arranged in superposed position with the cup terminal ofeach cell in surface contact with at least the major portion of the capterminal area of the adjoining cell to form a stack; and means forapplying pressure upon the stack to cause compression of the inwardlyextending portions of said grommets in the direction of the axis of thestack, individual fluid-tight sealing of the cell enclosures defined byeach cup and cap with their grommet, and low-resistance electricalconnection of said cells in series; the non-compressible character of,the said metal cups and caps preventing the possibility of applyingdestructive pressures upon the individual cells.

SAMUEL RUBEN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 879,724 Benjamin Feb. 18, 19081,425,721 Taylor Aug. 15, 1922 1,568,927 Stone et al Jan. 5, 19261,611,153 Benner et al Dec. 21, 1926 1,887,811 Ikin Nov. 15, 19322,116,091 Williams May 3, 1938 2,307,764 Deibel Jan. 12, 1943 2,307,766Deibel Jan. 12, 19.43 2,424,059 Scott July 15, 1947 FOREIGN PATENTSNumber Country Date 642,763 France May 9, 1928 4,512 Great Britain of1904 224,484

Switzerland Mar. 1, 1943

1. A BATTERY COMPRISING, IN COMBINATION, A PLURALITY OF CELLS; EACH OFSAID CELLS INCLUDING A SUBSTANTIALLY NON-COMPRESSIBLE METLAL ANODE SHELLAND A SIMILAR CATHODE SHELL RESPECTIVELY CONTAINING ANODE AND CATHODEMATERIALS AND HAVING OUTER SURFACES CONSTITUTING TERMINALS FOR THE CELL,A GROMMET OF ELASTIC INSULATIVE MATERIAL HAVING A PORTION EXTENDINGSUBSTANTIALLY TRANSVERSELY OF THE AXIS OF THE CELL INTERPOSED BETWEENCOOPERATING PORTIONS OF SAID SHELLS AND ADAPTED WHEN COMPRESSED BY THESHELLS IN THE AXIAL DIRECTION TO DEFINE WITH SAID SHELLS A SUBSTANTIALLYFLUID-TIGHT ENCLOSURE FOR THE CELL, AND AN ELECTROLYTE WITHIN SAIDENCLOSURE AND IN CONTACT WITH SAID ANODE AND CATHODE MATERIALS; SAIDCELLS BEING ARRANGED IN SUPERPOSED POSITION WITH THE ANODE TERMINAL OFEACH CELL IN SURFACE CONTACT WITH SUBSTANTIALLY THE ENTIRE CATHODETERMINAL AREA OF THE ADJOINING CELL TO FORM A STACK; AND MEANS FORAPPLYING PRESSURE UPON THE STACK TO CAUSE COMPRESSION OF THE TRANSVERSEPORTION OF SAID GROMMETS IN THE AXIAL DIRECTION, INDIVIDUAL SEALING OFSAID CELL ENCLOSURES, AND LOW RESISTANCE ELECTRICAL CONNECTION OF SAIDCELLS IN SERIES; THE NON-COMPRESSIBLE CHARACTER OF THE SAID METAL SHELLSPREVENTING THE POSSIBILITY OF APPLYING DESTRUCTIVE PRESSURES UPON THEINDIVIDUAL CELLS